Question

The triangles are similar.


What is the value of x?


Enter your answer in the box.

x =

Answer 1

25/5 = 5
and also 
15/3 = 5
so
(3x+ 8)/5 = 4
3x + 8 = 20
3x = 12
  x = 12/3
  x = 4

answer is x = 4

Answer 2

3x + 8 = 4 * 5 = 20
x = 4